1. Field of the Invention
The present invention relates generally to an impingement sprinkler, and more particularly to an innovative one which is used to absolutely limit the poke rod between two limit rods so as to enable steering of the impingement sprinkler.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Impingement sprinklers are extensively used for gardening irrigation and spraying, since circulating or reciprocating water sprinkling of the impingement sprinklers can be realized in an annular zone. In order to further improve its practicability, a tilting impingement sprinkler has been developed, allowing adjusting the outlet angle by tilting upwards or downwards (i.e. when tilting upwards, the parabolic sprinkling distance is bigger, or otherwise smaller) so as to meet the users' diversified demands. The present invention is intended to improve the steering structure of this tilting impingement sprinkler.
A conventional impingement sprinkler in accordance with the prior art shown in FIGS. 7 and 8 comprises a main frame 90 and a tubular structure 91 rotatably mounted onto a lower portion of the main frame 90, wherein the tubular structure 91 is adapted to be securely connected to an upright pipe (not shown). A sprinkling device 92 is laterally mounted onto the main frame 90 and an impinging device 93 is pivotally mounted on the sprinkling device 92. The impinging device 93 continually impinges the sprinkling device 92 for intermittently rotating the main frame 90 relative to the tubular structure 91 and forming an annular irrigating area when the sprinkling device 92 continually sprinkles and the sprinkled water continually forces on the impinging device 93.
A reversing device 94 is mounted onto the sprinkling device 92 for controlling the irrigating area of the impingement sprinkler. The reversing device 94 includes a poke rod 95 downward extending therefrom and two limit rods 96 horizontally pivotally mounted on the tubular structure 91, wherein an angle is formed between the two limit rods 96 and the angle is adjusted when the two limit rods 96 is pivotally moved relative to the tubular structure 91. The poke rod 95 is reciprocally moved within the angle formed by the two limit rods 96 when the sprinkling device 92 and the impinging device 93 are operated. The sprinkling device 92 is reversed when the poke rod 95 touches a corresponding one of the two limit rods 95. Consequently, the sprinkling device 92 has a sector irrigating area that has a central angle equal to the angle formed by the two limit rods 96.
However, the outflow angle of the sprinkling device 92 of the conventional impingement sprinkler is hardly adjusted. With reference to FIG. 9, the free may have a horizontal height over that of the two limit rods 96 when the sprinkling device 92 is upwardly tilted such that the two limit rods 96 lose their limit function to the poke rod 95 and the sprinkling device 92 does not be reciprocally operated. On the contrary, the free end of the poke rod 95 may be engaged to the tubular structure 91 and the sprinkling device 92 does not be smoothly steered when the sprinkling device 92 is downwardly tilted.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional impingement sprinkler in accordance with the prior art.